The long-term objective of the experiments proposed in the present application is to investigate adult age differences in several components of reading, ranging from word identification to sentence memory. All of the proposed experiments require young and older adult subjects to make a series of choice responses regarding visually presented words and sentences. The amount of time required to make these responses is the dependent variable of primary interest. Experiments 1-4 will all involve versions of the lexical decision paradigm, which requires that subjects decide, on each trial, whether or not a visually presented "target" letter string forms a real word. In Experiment 1, each letter string will be presesnted individually, and the type of information (e.g., pronounceability versus meaning) that is sufficient for making the lexical decision will be varied. A measure of basic visual functioning, contrast sensitivity to gratings of various spatial frequencies, will also be obtained in Experiment 1, and the relationship between contrast sensitivity and word identification time will be examined. Experiments 2-4 will use the lexical decision task to investigate identification of words in the context of sentences. Experiment 2 will examine the effect of the rate of presentation of the sentence context on word identification. Experiment 3 will vary the visual quality of the target letter string. In Experiment 4, the amount of time intervening between the context sentence and the target letter string will be varied. Experiments 2-4 will also investigate the ways in which word identification is affected by both the meaning of the context sentence and the difficulty (i.e., length and familiarity) of the target word. Experiment 5 will examine subjects' ability to make decisions about whole sentences rather than individual words. Experiments 6 and 7 will investigate aspects of recognition memory for visually presented text, by measuring the time required to decide whether particular words and sentences occurred in previously presented paragraphs. The proposed experiments are designed to determine whether an age-related slowing in the speed of information processing can account for age differences in component processes of reading, and to suggest ways in which text presentation can be best adapted for older adults.